大理岩规则齿形结构面剪切特性试验研究  

Experimental study of shear deformation characteristics of marble dentate joints

作　　者：周辉[1,2] 程广坦 朱勇 陈珺[1,2] 卢景景 崔国建[1,2] 杨聘卿 ZHOU Hui;CHENG Guang-tan;ZHU Yong;CHEN Jun;LU Jing-jing;CUI Guo-jian;YANG Pin-qing(State Key Laboratory of Geomechanics and Geotechnical Engineering. Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubci 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Water Conservancy and Civil Engineering,Shandong Agricultural University,Tai'an,Shandong 271018,China;China Coal Technology Engineering Group Chongqing Research Institute,Chongqing 400039,China)

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室,湖北武汉430071 [2]中国科学院大学,北京100049 [3]山东农业大学水利土木工程学院,山东泰安271018 [4]中煤科工集团重庆研究院有限公司,重庆400039

出　　处：《岩土力学》2019年第3期852-860,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51427803;No.51709257);国家重点基础研究发展计划(973)项目(No.2014CB046902)~~

摘　　要：为了便于研究不同粗糙度结构面岩体在压剪荷载作用下的剪切强度、剪切变形等力学特性的变化规律,制作了3种具有不同起伏高度的大理岩规则齿形结构面,锯齿高度分别为0、1、3 mm,开展了不同法向应力下的结构面直剪试验。试验结果发现,结构面剪应力-剪切位移曲线可分为两类:滑动破坏型和峰值剪断型;结构面沿锯齿先爬坡后剪断的破坏过程可划分为4个阶段:压密闭合阶段、爬坡剪胀阶段、锯齿剪断阶段、挤压碾碎阶段;锯齿结构面剪切强度-法向应力曲线近似呈三段线的特征,建立了三线段剪切强度准则;锯齿结构面剪切刚度-法向应力曲线呈上凸型特征,提出了结构面剪切刚度模型公式;锯齿结构面法向位移-剪切位移曲线呈先剪缩后剪胀的变化特征,提出了评价剪胀特性的经验公式。This study is aimed to investigate the regularities of the shear strength, shear deformation and other mechanical properties of joint rock mass with different roughnesses under compression-shear stress. Marble specimens were prepared with the dentate height of 0, 1 and 3 mm, respectively. Then direct shear tests were conducted on the marble specimens under different normal stresses.Experiment results show that curves of shear stress and displacement can be divided into two types: sliding failure type and peak shear type. The climbing-gnawing process of joints goes through four stages: the compaction stage, the climbing stage, the saw-tooth cutting stage and the completely crushing stage. The curves of shear strength with the normal stress of the dentate joint present more obviously three-segment line feature, and a trilinear shear strength criterion is established. The curves of shear stiffness with normal stress present a convex type, and a shear stiffness model is put forward. The dilatancy curves of dentate joint present firstly shear contraction and then shear dilation, and an empirical formula for evaluating shear dilation is proposed.

关 键 词：锯齿结构面 直剪试验 强度特性 剪胀特征 剪切刚度 

分 类 号：TU451[建筑科学—岩土工程]